\begin{tabular}{rrrr}
  \toprule
alpha & beta & mean & variance \\ 
  \midrule
39.70 & 43.38 & 0.48 & 0.00 \\ 
  49.47 & 62.74 & 0.44 & 0.00 \\ 
  19.34 & 17.61 & 0.52 & 0.01 \\ 
  19.91 & 22.81 & 0.47 & 0.01 \\ 
  32.39 & 39.05 & 0.45 & 0.00 \\ 
  18.57 & 19.00 & 0.49 & 0.01 \\ 
  5.57 & 7.58 & 0.42 & 0.02 \\ 
  6.43 & 10.93 & 0.37 & 0.01 \\ 
  7.46 & 7.35 & 0.50 & 0.02 \\ 
  3.36 & 3.46 & 0.49 & 0.03 \\ 
  3.70 & 4.67 & 0.44 & 0.03 \\ 
  5.03 & 4.22 & 0.54 & 0.02 \\ 
  3.94 & 4.40 & 0.47 & 0.03 \\ 
  4.47 & 5.56 & 0.45 & 0.02 \\ 
  2.39 & 2.19 & 0.52 & 0.04 \\ 
   \bottomrule
\end{tabular}
